The present disclosure relates to a developing device that supplies developer to an image carrier, and relates to an electrophotographic image forming apparatus including the developing device.
The electrophotographic image forming apparatus irradiates a circumferential surface of the image carrier (photosensitive drum) with light based on image information read from a document image or image information transmitted from an external device such as a computer, so as to form an electrostatic latent image. This electrostatic latent image is supplied with toner from the developing device so that a toner image is formed, and then this toner image is transferred onto a paper sheet. The paper sheet with the transferred image undergoes a process for fixing the toner image and is discharged to outside.
In recent years, along with the progress of color printing and fast processing, the structure of the image forming apparatus has become complicated, and fast rotation of a toner stirring member in the developing device is inevitable to support the fast processing. Particularly in a development system, which uses two-component developer containing magnetic carrier and toner, a magnetic roller (toner supply roller) that carries the developer, and a developing roller that carries only toner, only toner is carried on the developing roller with a magnetic brush formed on the magnetic roller at the part where the developing roller and the magnetic roller face each other, and further, toner that was not consumed for developing is removed from the developing roller. For this reason, scattering of toner easily occurs at the part where the developing roller and the magnetic roller face each other, and toner floating in the developing device deposits in the periphery of an ear-breaking blade (regulating blade). If the deposited toner coagulates and adheres to the developing roller, toner dropping may occur resulting in an image malfunction.
Accordingly, for example, there is known a developing device, which uses the two-component developer containing magnetic carrier and toner, the magnetic roller that carries the developer, and the developing roller that carries only toner, and includes a toner receiver support member that faces the developing roller or the magnetic roller, a toner receiver member disposed along a longitudinal direction of the toner receiver support member so as to receive toner dropped from the developing roller, and a vibration generating unit that vibrates the toner receiver member.
With the structure described above, toner deposited on the toner receiver member is shaken off by vibration, and hence it is possible to prevent toner deposition in the periphery of the regulating blade in the casing of the developing device and occurrence of toner dropping due to the toner deposition.